The function of sealed compressors for cooling fluids is well known in the art. Typically, an electric motor drive is built into a sealed housing or shell, and has a stator or electric armature affixed therein and a rotor assembly assembled into the cylindrical passage of the stator. This rotor assembly includes a rotor and a crankshaft which is inserted into the cylindrical passage of the rotor by interference fit. The reciprocating motion of the rotor and the piston in the compression chamber compresses low pressure gas into high pressure gas. The gas comprises typically freon or substitutes thereof. The low pressure gas comes from the closed loop system and enters a suction chamber through a cylinder head--suction muffler assembly. At the suction chamber, the low pressure gas is drawn into a compression chamber during the suction stroke of the reciprocating machine. A negative vacuum pressure is created. At the same time, lubricating fluid is also drawn into the suction chamber from a sump at the base of the crankshaft through a capillary tube for mixing with inert gas and lubricating the compression chamber. The compressed gas in the compression chamber is directed to the condenser of the system through a discharge valve, a discharge muffler, discharge line and tube discharge.
The prior art cylinder head-suction muffler assembly comprises a suction muffler, a capillary tube, a support plate, screws, and a cylinder head. The fabrication of the cylinder head requires at least one bore and two tightening holes to be made on the cylinder head. Similarly, the installation of the cylinder head to the suction muffler requires at least five steps: (1) inserting the suction tube of the suction muffler into the suction bore of the cylinder head, (2) fitting the capillary tube onto the suction muffler, (3) placing the support plate over the capillary tube and the two tightening holes, (4) inserting screws into the holes, and (5) tightening the screws. Because this assembly requires threaded fasteners, the prior art cylinder head-suction muffler assembly not only requires additional machining and handling, but the process of assembling it is time and labour intensive.
In an attempt to reduce the number of threaded fasteners and the time required for assembly, a few improvements have been made in the cylinder head-suction muffler assembly which are disclosed in, for instance, U.S. Pat. No. 5,207,564, and in European Patent Publication 195,486, where a screw-less specially-designed clips were used. However, the clips in these and other prior art assembly designs incorporated complex shapes and features. In addition, some of the designs required complicated locking features which needed precision in manufacturing of the parts and which required some effort to make and use. Because reduction in assembly time is a primary goal, it would be highly desirable to have components which are highly manufacturable in mass quantities, are easy to use, and are highly reliable.